Electrical contactor



June 15, 1965 F. R. HUGUS 3,189,716

ELECTRICAL CONTACTOR Filed Sepf. 15, 1961 2 Sheets-Sheet 1 INVENTOR: FRANK R. HUGUS ATTORNEY June 15, 1965 F. R. HUGUS 3,189,716

ELECTRICAL CONTACTOR Filed Sept. 15, 1961 INVENTOR: as FRANK R. HUGUS ATTORNEY United States Patent 3,139,715 ELECTRICAL CGNTACTGR Frank it. Hugns, Franklin, Pa., assignor to Zioy Manufao tuning tlompany, hittshurgh, Pa, a corporation of Pennsylvania 7 Filed 15, 11961, Ser. No. 133,519 1d (Iiairns. (Cl. Zed-147) This invention relates to a control device and more particularly to an electrical contactor of a structure whereby it is readily assembled, and disassembled for ease of inspection and replacement of parts.

Inasmuch as such devices are often operated under adverse conditions such as variable voltage, mechanical shock, corrosive atmospheres and high operating ternperature, it is necessary that the electrical contactor be built to provide a contactor that facilitates ease of disassembly for repair, replacement and overhauling. Previous known control devices are manufactured in such a manner that components subject to failure are parts of the device which cannot be readily replaced often requiring the removal of the entire contactor unit from its support whereby the contactor and its associated parts are disassembled entirely in order to inspect and replace such parts.

Applicants design provides a compact unit which permits component elements to be removed and replaced without removing the device from its present supporting structure.

Accordingly one object of this invention is to furnish a new and improved control device which can be readily assembled and disassembled.

Another object of this invention is to furnish a new and improved control device in which individual parts can be readily removed and replaced without general disassembly of the device.

Another object of this invention is to furnish a new and improved control device in which individual parts can be inspected without general disassembly of the device.

A specific object of this invention is to provide a new and improved control device which will allow a movable contact tip to be removed or replaced without dismounting other parts of the apparatus.

Another specific object of this invention is to provide a new and improved control device which will allow a stationary contact tip to be removed and replaced without dismounting any part of the apparatus other than a movable contact tip.

Another specific object of this invention is to provide a new and improved control device in which a movable contact assembly can be removed and replaced without dismounting the other parts of the apparatus.

Another specific object of this invention is to provide a new and improved control device in which an adjustable stop screw will provide for adjustment to accommodate varied results in manufacture and variations in operating voltage.

Another specific object of this invention is to provide a new and improved control device in which a solenoid coil can be removed and replaced without general disassembly of the device.

Another specific object of this invention is to provide a new and improved control device in which an arc chute assembly including a stationary contact can be removed and replaced without removing clamping screws or other parts of the device.

These and other objects of the invention will become more apparent upon consideration of the following detailed description of preferred embodiments thereof when taken in conjunction with the following drawings, in which:

FIG. 1 is a perspective view of a control device constructed in accordance with the principles of this invention;

PEG. 2 is a cross sectional view of the device as shown in FIG. 1 taken substantially along line 2-2 of P16. 1;

FIG. 2a is an enlarged view of a portion of the device as shown in FIG. 2 illustrating the installation of a drive screw;

MG. 3 is an exploded perspective view of the device as shown in FIG. 1;

FIG. 4 is a top plan view of a stop mem er showing a stop screw;

FIG. 5 is a front elevational partially sectional view of a stop member shown in FIG. 4.

In the drawings wherein like reference characters designate the same parts throughout the several views: there is shown in FIG. 3 a formed, generally rectangular, fiat metal top plate 9 having parallel top and bottom surfaces 7 and '7' respectively, a forward end 3 and a rearward end 19 parallel to each other and normal to a pair of lateral sides 12 and 14 oppositely equidistant from and parallel to a longitudinal central axis A-A of plate 9. An elongated open ended slot 16 extends longitudinally of plate 9 from the forward side 8 inwardly toward the central portion and is coaxial with the central axis A-A bifurcating the forward portion into leg members 17 and 1'7 respectively. The slot 16 has a parallel sides 19 blending into a substantially semicylindrical surface 18 the axis of which is normal to the top surface 7. The outer ends of the sides 19 adjacent the forward sides 8 are angularly outwardly chamfered as at 2d for a purpose to be described.

inwardly spaced from the surface 18 with its axis normal to the surface 7 and intersecting the longitudinal axis AA is a bore 22 which threadingly receives and rigidly secures a drive screw 23 which acts as a dowel to locate sub-assemblies of this apparatus relative to each other. The lateral width of the forward end portions of the leg members 17 and 17 is reduced by concave right angle corners 2?. Immediately rearward of each concave corner 28 the leg members 17 and 17 have pairs of longitudinally spaced bores 39 extending therethrough respectively, the axes of which are normal to the upper surface 7. Each pair of bores 3% has a common center line closely adjacent and parallel to the lateral sides 12 and 14 respectively. A pair of slots 32 located longitudinally of the bores 30, extend laterally inwardly of the plate 9 from the sides 12 and 14 respectively. The slots 32 have a common longitudinal axis normal to the central axis A-A and have bottom surfaces laterally aligned with the surfaces of the bores 35), adjacent thereto, nearest the axis A-A. The bores 3a) and the slots 32 are suitably spaced to allow the mounting of a suitable mounting bracket (not shown) for a suitable mercury switch of a type well known in the art.

A generally keyhole shaped slot 24- through the central portion of the plate 9 has the axes of its generally semicircular ends normal to the surface 7 and intersecting the axis AA and is so oriented that the smaller end of the keyhole slot 24 is nearer the rearward edge of plate 9. This slot is so located and shaped that a cap screw 62, provided with a captive loclrwasher 162' (see FIG. 1), may be inserted head first through the larger end of the slot and upon being displaced rearwardly in the plate 9 will engage the smaller end of the keyhole slot.

Reference to downwardly, upwardly, forward, rearward and the like found in this description is made for conyenience of explanation and is not intended to limit the scope of this invention. I

A formed generally rectangular mounting leg 34 abuttingly engages the undersurface '7' of the plate 9 at its rearward edge, with a rear surface 33 of the mounting leg 34 substantially coplanar with the forward surface of a rectangular notch 36 (see FIG. 2) in the rearward end 10. Two cap screws it are slidably received by a pair of bores (not shown) through the rearward portion of plate a and threadedly received by a pair of spaced threaded bores in the upper surface of the mounting leg 34 to rigidly secure the abutting engagement of the mounting leg 34- with the plate a, The mounting leg 34 (see FIGS. 1 and 3) has suitable means such as threaded bores 35 for mounting the entire device on a suitable insulated panel (not shown) as is well known in the art. The lower end portion of mounting leg is bifurcated to form two spaced hinge leg portions 38 and 33 respectively, having transverse axially aligned bores 44 therein respectively. The two hinge leg portions 33 and 38', respectively, have tforward projecting portions with laterally aligned rectangular slots 42 therein extending rearwardly from the forward surface thereof. A formed stop member 7% (FIGS. 4 and 5) having a fiat upper surface 79 has a triangular front portion and a rearwardly extending rectangular rear portion 30. A bore 86 normal to the top surface 79 extends through the apex of the triangular portion and rigidly receives a suitable lock nut 88 for retaining a stop screw 90. The base portions of the triangular portion of the member 78 extend laterally outwardly from the rectangular portion 3%? forming wings 82 to be rigidly received in the slots 42 respec-' tively. The rear portion 8% is of such dimensions as to be suitably slidably engaged with a rectangular slot 39, formed by hinge legs 33, 3% in the lower portion of leg member 34. The top surface 79 is parallel to and slightly above the axis of a semicylindrical transverse recess 34 in the rectangular portion 8%, which recess 84 is axially aligned with the transverse bores 44% when the rectangular portion 84) is slidably engaged in the rectangular slot 39 to receive an elongated cylindrical metal hinge pin 41. Upon the insertion of the hinge pin 41 in the transverse bores 44 and through the semicylindrical recess 34 with the wings 82 slidably received by the slots 42, the stop member 78 becomes a rigid, forward projecting, downward sloping portion of this assembly substantially paral- -lel to the top plate 9 (see PEG. 2). 7

An inverted U-shaped armature member 48, formed of magnetic material, has a hat top surface 47 and a pair of laterally spaced depending legs 49 each of which has a rearwardly extended hinge portion 5b. The hinge portions so have axially aligned bores 55 therethroug-h with the common axis parallel to the top surface 47. Each bore 55 rigidly receives a short cylindrical bushing 51 having its inner end (not shown) coplanar with the inner surface of the hinge area St) and having its outer end protruding from the outer surface of the hinge area 50. The bores 55 pivotably receive the hinge pin t! mating with the transverse bores 44 to form a pivotable hinge member. The hinge pin '41 is secured by a set screw 45 threadedly engaged in a threaded bore 46 in the bottom surface of the hinge leg portion 38 which suitably intersects one of the transverse bores 44 so that the set screw 45 can rigidly engage the surface of the pin 41 to secure it in position. The forward edge of each depending leg has a rearwardly extending elongated U-shaped notch 52, to the rear of which is a threaded bore 54 coaxial with a corresponding bore in the opposite leg 4-} The bores 54 and the notches 52 are suitably positioned for the mounting of an auxiliary armature piece (not shown). Centrally located in the top portion of armature member 48 and extending there/through are two longitudinally spaced bores 53 to slidably receive a pair of machine screws 56 threadedly engaged in two locknuts 61' (see FIG. 2) rigidly engaged in a pair of spaced bores 61 suit- :ably located on the longitudinal axis of an elongated, formed mounting plate 62 having an upper surface 59 abuttingly engaged with the under surface of the central portion of the armature member as being rigidly engaged therewith by the cap screws 56. The mounting plate 62 has a narrow downwardly sloping forward portion 67 4%, and two depending laterally spaced hinge legs 65. The hinge legs 65 have axially aligned transverse bores 68' which rigidly engage an elongated cylindrical hinge pin as.

An elongated rectangular carrier 64 having a bottom surface 69 has .a transverse bore intermediate its ends having an axis parallel to the bottom surface 69, to pivotably engage the hinge pin 63. The rearward portion of the carrier @4 is provided on its up er surface with a short cylindrical boss (not shown) to suitably and internally engage the base of a short, cylindrical, compression type, biasing spring 66. It is to be noted that the carrier 64- pivot-ably mounted on the hinge pin 68 has its rearward portion biased downwardly by the slightly compressed spring on acting between the rearward portion of the carrier 6'4 and the central portion of the mounting plate 62 so that the forward portion of the carrier 64 is biased in an upward direction against the forward portion 67 of the mounting plate 62 acting as an abuttingly engaged detent to limit the pivoting action of the carrier 64.

A formed, semi-elliptically cross sectional movable contact member 74 has a fiat rear surface 77 with two spaced leg members 76 extending from its rear surface 7 7 to form an elongated U-shaped slot with its longitudinal axis normal to the rear surface 77. The leg members 7;; of the contact member 74 overlappingly engage the lower surface '59 of the forward portion of the carrier 64 and are rigidly secured in such engagement by a pair of machine screws '72 threadedly engaged in a pair of threaded bores 71) in the forward portion of the carrier 64, the screws 72 being slidab-ly engaged in the U-shaped slot 75. It is to be noted that the movable contact mem ber 74, the carrier 64, the biasing spring 66 and the mounting plate 62 form a movable contact assembly 60. There has now been assembled and pivotably mounted on leg member 34 at its lower end an armature assembly 53 comprising movable contact assembly as and armature member 48. The armature assembly 53 is restrained in its downward motion by the adjusting screw mounted in the stop member 78 which in turn is rigidly engaged by leg member 34 (see FIG. 2).

An elongated flexible conductor 94 (a woven metal strap) has three bores therethrough along its longitudinal axis, one bore being adjacent one end of the conductor 94 and two adjacent the other end. The end of the conductor 94 having a single bore is overlappingly engaged with the rearward portion of the upper surface 7 of the top plate 9, the single bore being slidingly engaged with a cap screw 13 threadedly received by a threaded bore 26 (see FIG. 2) in the central rearward portion of the top plate 9. An inverted U-shaped terminal bracket 15 hav ing the ends of its leg portions engaged with the top surface 7 of the top plate 9 is also secured in position by the cap screw 13 passing through a clearance bore in the bight portion thereof. The bracket 15 bridges over the flexible conductor 94 leaving an unoccupied space 21 t-herebetween. The space 21 will be occupied by a termi nal fitting (not shown) of a conductor supplying electric power to this device when the device is mounted on a machine. The flexible conductor 94 is trained downwardly through the notch 36, along the rear surface 33 of the leg member 34- and carried forward along the underside of the stop member 78 and overlapping 1y engaged with the rearwardly extending legs 76 of the movable contact member 74 by the act-ion of the machine screws '72 threadedly engaged in the threaded bores 76 of the carrier 64. The machine screws '72 are received by the two bores adjacent the end of the flexible member 94. Motion of the armature assembly 53 pivoting about hinge pin 41 necessitates the use of the flexible conductor 94- for maintaining a continuous electrical connection between the movable contact member 74 and the afo=rementioned terminal end of an electrical conductor to be situated in the unoccupied space 2]..

Referring again to FIG. 2; a suitable hollow cylindrical coil 158, of a type well known in the art, and a cylindrical magnetic pole piece 166 having an upper portion 157, and a lower portion 159, together comprise a solenoid magnet 156. The lower portion 159 of the cylindrical pole piece 16% has a radially extended cylindrical portion 163 forming an outwardly extending annular surface 165 which abuttingly contacts the bottom surface of the hollow cylindrical coil 158 adjacent its inner periphery. The upper portion 157 has a threaded axial bore 164 therein by which a threadedly engaged cap screw 162, slidably inserted through the larger end of the keyhole slot 24, and suitably positioned within the smaller extremity thereof, supports the solenoid magnet 156 in abut-ting engagement with the under surface 7 of the top plate 9.

A generally L-shaped rectangularly cross sectioned non-magnetic bracket 10-2 (FIGS. 2 and 3) has a hori zontal leg 102' with a top surface 163 and a depending leg 1115 (see FIG. 3) having a bottom surface 1119 and a rear surface 107. The top surface 103 is parallel to the bottom surface 1129 and both are normal to the rear surface 107. The horizontal leg 1112' has a pair of longitudinally spaced threaded bores 104 extending therethrough having axes normal to surface 1113. Surface 103 is separated, by a transverse rectangular groove 1 14, int-o two rectangular raised portions at the forward and rearward extremity of horizontal leg 1112', in which the axes of the bores 104 are centrally located. The lower extremity of depending leg 1115, having a forward surface 107', has a concave right angle corner 116 in its forward surface. A threaded bore 1% having its axis centrally located within the right angle corner 11d and normal to the rear surface 107 of the depending leg 195, extends therethrough. The forward surface 1d?" of the depending leg member 165 is arcuately recessed to provide clearance for a hollow cylindrical blowout coil 112 having two holes in the upper extended end and one hole in the lower extended end of the blowout coil 112, which may be any of several designs well known in the art, with an axial bore 113 formed by the innermost windings. There are also two longitudinally spaced transverse bores 1&8 through depending leg 105 for a purpose to be described. An arcuately shaped flat member 1 16 called an arc horn, of a type well known in the art, having a mounting hole in its lower extremity and extending therethrough, is suitably secured by cap screw 1111 passing through the mounting hole, thence through the single hole in the lower end of the blowout coil 1 12 which is suitably abuttingly engaged with the lower end of the arc horn; the cap screw 101 then being engaged in threaded hole 1116 at the bottom of the depending leg 195 of the bracket 1112. An L-sha ped metal plate stationary contact $6 has one member formed into two extended legs 98 (see FIG. 3) forming a rectangular slot 18d of a suitable size to slidably engage cap screw ltlll. $tationary cont-act member 96 is slidably engaged in the right angle concave corner 110, between the lower end of the depending leg 105 and the lower end of the blowout coil 112, with both of which it is abuttingly engaged by tightening the cap screw 101. Overlappingly engaging the upper end of the blowout coil 112 is a threaded and slotted forward terminal 118 of a type well known in the art, having two spaced threaded bores 1 17 with axes parallel to central axis AA and lying in the vertical plane thereof, suitably located for engaging two machine screws 111. The machine screws 111 secure the overlapping engagement of the blowout coil 112 with the terminal 118. The forward terminal 118 also contains two transverse mounting holes 119 extending therethrough, which together with the transverse mounting holes 108 in bracket 1-32 will suitably slidably engage four mounting cap screws 124. These cap screws 124 are used for the mounting of two generally rectangular, mated, hollow molded insulating blocks 126 having matingsurfaces 12% and being suitably shaped to enclose the aforemem tioned blowout coil 112 and are m 116 together with the stationary contact 96. A shall-ow rectangular groove 121 in the forward, portion of each mating surface 120' combines with the corresponding groove 121 in the opposite insulating block 1 25} to form a blowout slot 127 (see PEG. 1) when the insulating blocks 120 are suitably positioned in abutting engagement with the blowout coil 12, the bracket N2 and the forward terminal 118. The outer surfaces 1-242 of the molded insulating blocks 1213 are suitably recessed to allow the abutting engagement of a generally rectangular fiat blowout plate 122, of a type well known in the art, in such position that the outer surface of the blowout plate 122 is coplanar wit-h the outer surface 122' of the block 126). An elongated magnetic metal mounting cylinder 123 has an axial bore therethrough provided with internal threads at both ends of this bore suitable to threadedly engage cap screws 1:25 to secure the blowout plates 1 12. The cylinder 123 is slidably engaged in the axial bore 113 of blowout coil 112.

The hereinbefore described members, namely the racket 1412, the blowout coil 11-2, the arc horn 116, the forward terminal 118, the hollow molded insulating blocks 120, the blowout plates 122, and the mounting cylinder 1'23 together with associated parts are assembled to form an arc chute assembly 126, of a type well known in the art, which may be produced from various components available on the market.

In FIG. 3 a formed, insulating, generally rectangular lower clamp plate 128 has its bottom surface 131 abuttingly enga ed with the top surface 163 of bracket 102, and has an upper surface 129 parallel thereto with a forward side 133 normal to the upper and lower surfaces. Extending from the upper surface 129 of the clamp plate 123, having axes normal thereto and intersecting the central axis AA are two spaced bosses 130 and 132 rearward and forward bosses respectively. The rearward boss 139 has an external cylindrical surface suitable to abuttingly engage the semi-cylindrical surface 18 in top plate 9 and has internally a stepped bore 137 coaxial with the external cylindrical surface of the rearward boss 13%} with its larger portion beginning at the upper surface of the boss 13%, and a smaller portion 186 extending through clamp plate .128 to its bottom surface 131. The forward boss 132 has semi-cylindrical ends and is elongated along axis A-A beyond forward surface 133 forming an extension of clamp plate 128. The rearward facing external surface of boss 132 abuttingly engages the charnfers 20 in top plate 9. Superimposed on boss 132 and coaxial with the forward semi-cylindrical portion thereof is a short cylindrical boss 134, having a bore 138, coaxial therewith, extending through the bosses 134 and 132. The bores 136, 138 are suitably located to slidably engage two cap screws 152 threadably engaged in the threaded bores 1434.

A formed insulating, generally rectangular upper clamp plate 141 has a semicircular rearward end 142 (see FIG. 3) and a forward edge 143 with a U-shaped protective ridge 144 on its upper surface. The open end of this U-shaped ridge 144 is directed toward the forward edge 143 and the rearward portion of the U-shaped ridge is inwardly adjacent the semicircular rearward end 142 of clamp plate and concentric therewith. Clamp plate 14-1) has a lower surface 141 with a rearward boss 146 and a forward boss 143 downwardly extended therefrom. The forward boss 143 is shaped to mate with the forward boss 132 of lower clamp plate 128 hereinabove described and is provided with a shallow counterbore 149 suitably formed to slidably receive the boss 134 of lower clamp plate 128. Rearward boss 14s is of a size and location to be slidably received by the larger end of stepped bore 137 in rearward boss 13%). Coaxial with the above mentioned bosses and having their axes perpendicular to lower surface 141 are two spaced bores 15s suitably located a to match bores 136 and 138 of lower clamp plate 123 and suitably slidable to receive the cap screws 152 engaged in threaded bores 104. A shallow counter-bore 154, in the bottom surface 141, is suitably located on central axis AA forwardly adjacent the semicircular rearward end 142 of plate 140 to engage the head of the drive screw 23 (see FIG. 2a).

The forward extending legs 1-7 and 17 of top plate 9 are inserted between the upper clamp plate 140 and the lower clamp plate 128 and moved forward until boss 136 is firmly seated against semi-cylindrical surface 18, and the boss 132 abuttingly engages radius chamfers 20 on top plate 9. Tightening cap screws 152 will bring the shallow counter bore 154 into engagement with the head of the drive scr w 23, suitably locating the separate parts of this apparatus and completing its assembly.

A method of operation for this control device is as follows: When coil 158 is energized by a small current from a suitable external source (not shown), concentrated magnetism in the pole piece 166 attracts the armature member 48 bringing the movable contact member 74, secured thereto as part of the armature assembly 53, into abutting contact with the stationary contact member 96. The movable contact member 74 is biased by spring 66 upwardly in a clockwise direction so that abutting contact is made with the stationary contact 96 before armature member 48 is stopped by contact with the lower end 163 of the cylindrical pole piece 166, at which time the biasing spring 66 is slightly compressed. Upon the establishment of such contact, large currents from the external source may be conducted from the rear terminal bracket 15 through the flexible conductor 94 and the movable contact '74, thence through the stationary contact 96 and the blowout coil 112 to the forward terminal 118 through suitable conductors to a motor or other device, in which a large electric current is used, and thence back to the source, completing the circuit. Upon interruption of the current through coil 158, by action of a suitable disconnect switch (not shown) the magnetism in the pole piece 160 is also interrupted. The reaction of the biasing spring 66 pushing up on the movable contact member 74 causes the armature to move quickly downward pivoting about pin 41 a very short distance, after which gravity and inertia continue the motion, suddenly breaking the abutting contact between the movable contact member 74 and the stationary contact member )6, thus inactivating the motor or other electrical device. This sudden breaking of the contact reduces the burning of the contact surfaces 74 and 96 which would result if the contacts were slowly separated. The are formed upon breaking the contact, due to interruption of the large current, is caused to blow out through the slot 127 in the arc chute 126, by action of the blowout plates 122, the blowout coil 112 and the arc horn 116, in a manner well known in the art.

In the present device, loosening of the two cap screws 72 securing the movable contact 74 on the movable contact assembly 60 will allow the removal of movable contact 74 for inspection and replacement.

The stationary contact 96, which is subject to much burning during normal operation of this device, is replaced by inserting a screw driver or an Allen wrench through the slot 127, formed by the molded insulating blocks 126, and loosening the cap screw 161 so that the stationary contact member 96 may slide downwardly and out of engagement with the bracket 102 and the blowout coil 112.

Thus both of the contact parts of this control device, such as movable contact 74 and stationary contact 96 highly subject to thermal and mechanical damage, may be inspected and replaced without further disassem'bly of the apparatus.

Regulation of adjusting screw 90 (see FIG. 2) determines the extreme lower position of armature assembly 53 in relation to the pole piece 160. The distance may be decreased when the device is operating on low voltage, which results in less powerful magnetism than is normally present, unable to move the armature at a normal distance from the pole piece. Under conditions of higher voltage than normal, regulation of the adjusting screw 94) may be used to increase the distance between the contact surfaces of the contact members 74 and 96, in the open position, to prevent excessive burning at the contact points. Such'burning is usual in devices of the prior art when operated on a voltage higher than normal.

By loosening the clamp plate mounting screws 152 a few turns, the arc chute assembly 126 is disassembled from the rest of the device. After this has been done it is possible to dismount the solenoid coil 156 by loosening its securing capscrew 162, and moving the coil away from the. mounting leg 34 and dropping the head of cap screw 162 through the enlarged portion of key slot 24.

To disengage the movable contact assembly 66 from the rest of the apparatus for inspection, repair or replacement, remove the machine screws 72 in the forward portion of the carrier 64, allowing the separation of contact member 74 and flexible conductor 94 from this assembly, then remove the set screw 45 in hinge leg 38 of leg member 34 (see FIG. 3) and slide out hinge pin 41. This action allows the armature assembly 53 to be disengaged from the apparatus. By removing the two machine screws 56 which secure the engagement of the movable contact assembly 60 with the armature member 43, the movable contact assembly 60 may be dismounted for inspection and replacement. It is to be noted that the screws 56 can be removed and the movable contact assembly 66 dismounted from the unit without previously removing armature assembly 53 therefrom whenever the solenoid coil 158 and the arc horn 126 have been previously removed.

Having described a preferred embodiment of this invention in accordance with the patent statutes, it is to be realized that modifications thereof may be made without departing from the broad spirit and scope of the invention. Accordingly it is respectfully requested that this invention be interpreted as broadly as possible and be limited only by the prior art.

What I claim is:

1. An electrical contactor comprising, a support assembly having a plate portion, an elongated open ended slot extending inwardly from one side of said plate portion, an arc chute assembly having an outer surface with a boss portion extending outwardly therefrom said boss being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one side of said plate portion, a clamping plate abuttingly engaging the other side of said plate portion, releasable means having a portion thereof extending freely through said clamping plate and said slot into engagement with said chute assembly to secure said chute assembly to said mounting plate, an operating coil supported by said support assembly, and cooperable contact means supported by said assemblies, respectively.

2 An electrical contactor as set forth in claim 1 wherein said plate portion has a first bore radially overlapping a smaller second bore to form a keyhole slot, said operating coil being connected to said plate portion by retaining means having a head portion passing through said first bore and a reduced diameter neck portion slidable from said first bore into said second bore to support said operating coil with said head portion engaging said other surface of said plate portion. 7

3. An electrical contactor comprising, a support assembly having a plate portion, an elongated open ended slot extending inwardly from one side of said plate portion, an arc chute assembly having an outer surface with two boss portions extending outwardly therefrom one of said bosses being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one side of said plate portion the other of said bosses abuttingly engaging the side of said plate portion adjacent the open end of said slot, a clamping plate abuttingly engaging the other side of said plate portion, releasable means having a portion thereof extending freely through said clamping plate and said slot into engagement with said chute assembly to secure said chute assem bly to said mounting plate, an operating coil supported by said support assembly, and cooperable contact means supported by said assemblies, respectively.

4. An electrical contactor comprising, a support assembly having a plate portion, an elongated open ended slot extending inwardly from one side of said plate portion said slot having outwardly flared end portions at said open end, an arc chute assembly having an outer surface with two boss portions extending outwardly therefrom one of said bosses being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one side of said plate portion the other of said bosses abuttingly engaging said flared end portions of said slot, a clamping plate abuttingly engaging the other side of said plate portion, releasable means having a portion thereof extending freely through said clamping plate and said slot into engagement with said chute assembly to secure said chute assembly to said mounting plate, an operating coil supported by said support assembly, and cooperable contact means supported by said assemblies, respectively.

5. In an electrical contactor the improvement comprising: a support assembly having a generally rectangular plate portion, an elongated open ended slot extending inwardly from one end of said plate portion, an arc chute assembly having an outer surface with an internally threaded hollow boss portion extending outwardly therefrom said boss being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one surface of said plate portion, a clamping plate abuttingly engaging the other surface of said plate portion, threaded retaining means having a portion thereof extending freely through said clamping plate and said slot and being threadedly engaged with said internally threaded boss portion to releasably secure said chute assembly to said mounting plate, an operating coil supported by said support assembly, and cooperable contact means supported by said assemblies, respectively.

6. In an electrical contactor the improvement comprising: a support assembly having a generally rectangular plate portion, an elongated open ended slot extending inwardly from one end of said plate portion, an arc chute assembly having an outer surface with two internally threaded hollow boss portions extending outwardly therefrom, one of said bosses being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one surface of said plate portion the other of said bosses abuttingly engaging the said one end of said plate portion, a clamping plate abuttingly engaging the other surface of said plate portion, threaded retaining means having a portion thereof extending freely through said clamping plate and said slot and being threadedly engaged with said internally threaded boss portions to releasably secure said chute assembly to said mounting plate, an operating coil supported by said support assembly, and cooperable contact means supported by said assemblies, respectively.

7. In an electrical contactor the improvement comtit id prising: a support assembly having a generally rectangular plate portion, an elongated open ended slot extending inwardly from one end of said plate portion said slot having outwardly flared end portions at said open end, an arc chute assembly having an outer surface with two internally threaded hollow boss portions extending outwardly therefrom one of said bosses being closely slid ably received within said slot with said outer surface of said chute assembly abuttingly engaging one surface of said plate portion the other of said bosses abuttingly engaging said flared end portions of said slot, a clamping plate abuttingly engaging the other surface ofsaid plate portion, threaded retaining means having a portion thereof extending freely through said clamping plate and said slot and being threadedly engaged with said internally threaded boss portions to releasably secure said chute assembly to said mounting plate, an operating coil supporting coil supported by said support assembly, and

cooperable contact means supported by said assemblies, respectively.

8. In an electrical contactor the improvement com prising: a support assembly having a generally rectangular plate portion, an elongated open ended slot extending inwardly from one end of said plate portion, an arc chute assembly having an outer surface with an inter nally threaded hollow boss portion extending outwardl therefrom said boss being closely slidably received within said slot with said outer surface of said chute assembly abuttingly engaging one surface of said plate portion, a clamping plate abuttingly engaging the other surface of said plate portion, threaded retaining means having a portion thereof slidably extending through said clamping plate and said slot being threadedly engaged with said internally threaded boss portion to releasably secure said chute assembly to said mounting plate, an operating coil supported by said support assembly, stationary contact means releasably supported by said are chute assembly, armature means pivotably supported by said sup port assembly, movable contact means releasably mounted on said armature means to contact said stationary contact means when said coil is energized.

9. An electrical contactor as set forth in claim 8 wherein an adjustable stop means engages said armature means to provide selective positioning :of said movable contact relative to said stationary contact when said coil is not energized.

10. An electrical contactor as set forth in claim 8 wherein said stationary contact has a bifurcated mounting portion to permit easy removal of said stationary contact.

References Cited by the Examiner UNITED STATES PATENTS 1,155,626 10/15 Steen 200-147 2,967,921 1/61 Carver 200-144 3,023,286 2/62 Bourne et al. 20087 FOREIGN PATENTS 423,673 7/47 Italy. 602,354 5/48 Great Britain. 859,137 1/ 61 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

0 ROBERT K. SCHAEFER, Examiner. 

1. AN ELECTRICAL CONTACTOR COMPRISING, A SUPPORT ASSEMBLY HAVING A PLATE PORTION, AN ELONGATED OPEN ENDED SLOT EXTENDING INWARDLY FROM ONE SIDE OF SAID PLATE PORTION, AN ARC CHUTE ASSEMBLY HAVING AN OUTER SURFACE WITH A BOSS PORTION EXTENDING OUTWARDLY THEREFROM SAID BOSS BEING CLOSELY SLIDABLY RECEIVED WITHIN SAID SLOT WITH SAID OUTER SURFACE OF SAID CHUTE ASSEMBLY ABUTTINGLY ENGAGING ONE SIDE OF SAID PLATE PORTION, A CLAMPING PLATE ABUTTINGLY ENGAGING THE OTHER SIDE OF SAID PLATE PORTION, RELEASABLE MEANS HAVING A PORTION THEREOF EXTENDING FREELY THROUGH SAID CLAMPING PLATE AND SAID SLOT INTO ENGAGEMENT WITH SAID CHUTE ASSEMBLY TO SECURE SAID CHUTE ASSEMBLY TO SAID MOUNTING PLATE, AN OPERATING COIL SUPPORTED BY SAID SUPPORT ASSEMBLY, AND COOPERABLE CONTACT MEANS SUPPORTED BY SAID ASSEMBLIES, RESPECTIVELY. 